Swelling of the patient’s right middle finger can be caused by the following reasons: first, trauma: if there is an old trauma to the middle finger, resulting in damage to the soft tissue ligaments around the middle finger joint, swelling around the middle finger joint can occur. This should be diagnosed according to the history of trauma, as well as X-rays and MRIs. Second, tenosynovitis: it can lead to symptoms of swelling and pain in the metacarpophalangeal joint of the middle finger. Third, gout or rheumatism, rheumatoid: can be accompanied by pain in multiple joints, as well as wandering pain. Fourth, osteoarthritis: osteoarthritis is a degenerative manifestation, which can cause swelling, pain and deformity of the fingers, etc. At this time, it is necessary to carry out relevant X-ray examination as well as physical examination for diagnosis and treatment.